WO1990005842A1

WO1990005842A1 - Internal combustion engine

Info

Publication number: WO1990005842A1
Application number: PCT/CH1989/000184
Authority: WO
Inventors: Nicholas J. Johannes
Original assignee: Johannes Nicholas J
Priority date: 1988-11-18
Filing date: 1989-10-20
Publication date: 1990-05-31
Also published as: JPH03502354A; EP0396676A1; US5056486A; EP0396676B1; CH677004A5

Abstract

A multi-valve engine has a plurality of inlet channels (2, 3) each having a choke (6) and a fuel injection (7) as well as an intake valve (5). The intake channels, which run in different directions, are arranged so that the gas stream which flows through them into the cylinder forms a vortex. At low engine speeds, only one intake channel is open and other inlet channels open in succession. Because of the differences in cross-sectional area of the channels, the gas flow rate is greatest in the intake channel which opens first and becomes progressively smaller in the intake channels which open in succession. By means of variable interconnection of the channels, a higher maximum output with good torque characteristic is obtained as well as optimal fast combustion as a result of strong turbulence throughout the entire production of torque.

Description

V e r b r e n n g s m o t o r

The invention relates to an internal combustion engine with at least one exhaust valve and more than one intake valve per cylinder and with a control device for the intake and exhaust valves.

Because the performance of an internal combustion engine increases with the stroke size of the individual cylinders and the speed increases, the masses of the pistons that are to be moved are large in the case of a large displacement, which limits the speed, making high-performance engines multi-cylinder with an ± smaller displacement of the individual cylinder and built for high speeds, which, however, lose torque in the lower speed ranges. In order to achieve an optimal gas change in the cylinder, which determines the engine power, both at low and at high speeds, various solution proposals have already been made, such as length-adjustable intake ducts, because the intake duct is narrow and long for an elastic and high-torque engine characteristic the highest possible performance of the engine should be relatively short and large in diameter. In other proposed solutions, a load at Teil¬ ^'semi-closed double carburetor or abschalt¬ bare valve actuation is used, but with only partial success which can be achieved.

A further suggestion in this direction is the variable valve control, with which different valve lift heights and valve overlaps of different sizes can be set for the different speed ranges with different cam profiles. Valve overlaps represent a method of increasing performance that has been used in engine construction for a long time. The low vacuum created at the end of the exhaust cycle due to the mass of the escaping gas column is inlet duct exploited, the exhaust vacuum sucking in the fresh gas, which is under a slight positive pressure, by opening the inlet valve at an early stage, so that a larger filling quantity is achieved due to the acceleration of the gas column. The longer the cylinder has to travel from the intake valve to the exhaust valve, the earlier the intake valve can be opened without fresh gas escaping in the exhaust. However, this fact has not yet been used consistently in multi-valve engine construction.

There have been multi-valve engines for a long time, but in which the overlap times have to be kept very small because the inlet valves and outlet valves located close to each other are opened simultaneously. The advantages that can be achieved with multi-valve engines are that higher speeds can be achieved with no, and therefore lighter, valves, and that due to the fact that the total circumference of two valve plates is larger than the circumference of a single, albeit larger, valve plate, a higher gas throughput is achieved can be. However, if there is a better filling quantity in the cylinder and a turbulence that is very desirable for the uniform, rapid combustion of the gas particles, which arises due to the swirling inflow of the gas flow into the cylinder due to the arrangement of the inlet valve to the side of the center of the axle, advantages that have long been known in engine construction represent of two-valve engines, these advantages are lost again in the multi-valve engines known today, because less advantageous collision turbulence arises in the case of several intake valves, so that the slower and irregular combustion resulting therefrom leads to auto-ignition, in particular at higher gas throughput and speeds. The desired turbulence with vortex formation can arise if one of the two inlet ducts is closed at partial load in a multi-valve engine, but this vortex breaks down again immediately as soon as the adjacent inlet duct is opened under greater load and the previously mentioned disadvantageous

lying inlet channel is the first to be opened, by means of which measure larger valve overlap times can be achieved.

In a preferred embodiment, at least one of a plurality of separate intake ports opens essentially from above and at least one further intake port from the side obliquely with an inclined position pointing in the same circumferential direction with each additional inclined intake port into the cylinder head. Accordingly, there may be two or three or even four inlet channels, which are arranged distributed over the circumference of the cylinder head at substantially the same angle intervals. Two inlet ducts from above and two inlet ducts can open diagonally into the cylinder head from the side, but they open ^' more or less markedly in the same circumferential direction into the cylinder head in such a way that the gas flow swirls into the cylinder head Zylin¬ flows and the desired turbulence arises.

One or two exhaust valves can be provided per cylinder. In each row of cylinders, however, the exhaust ports are arranged on the same side ». Known multi-valve engines with swirl characteristics result in a very cumbersome construction when the exhaust ports and intake ports are arranged crosswise on the individual cylinders from above.

In an expedient embodiment, the inlet channels have a different size of their clear cross section, with which different gas velocities are achieved. In this ^"way it is when aufein¬ other following switching to gradually lower Gasge¬ speeds designed intake ports aufeinanderfol¬ open quietly the individual intake channels for higher speed ranges. With this configuration of the cylinder with increasing stroke position and stroke speed of the piston is optimally charged and swirls and slows at maximum stroke. Overall, the variable channel activation a higher maximum output with good torque characteristics.

Further details and advantages of the invention will become apparent from the following description and the drawings, in which the invention is shown purely by way of example. Show it:

1 schematically and in a diagrammatic representation a three-valve cylinder head with associated channels;

2 shows a plan view of the cylinder head according to FIG. 1, without flaps and nozzles;

3 shows a top view schematically of a three-valve cylinder head with a different arrangement of the valves and channels;

4 shows a top view schematically of a four-valve cylinder head;

5 shows a top view schematically of a four-valve cylinder head with a modified arrangement of the channels and valves;

6 shows a top view schematically of a five-valve = cylinder head.

1 open into the cylinder head 1 of a cylinder of an internal combustion engine, not shown, a first intake port 2 essentially from above and a further intake port 3 pointing obliquely from the side in the circumferential direction, so that the gas flow in a spiral shape according to the arrows 4 in the cylinder flows in. The two inlet channels 2 and 3 are each closed off by a valve 5. Furthermore, each inlet duct has an air flap 6 and a fuel supply 7. which are continuously adjustable. Depending on the flap position, fuel is processed accordingly. An intake channel ^is' pay for low Dreh¬ just opened and then additionally for higher speeds the second inlet channel geöff¬ net.

An outlet channel 8 with an outlet valve 9 is arranged opposite the two inlet channels 2 and 3. The valve plates of the inlet valves 5 and the valve plate of the outlet valve 9 are inclined with respect to the cylinder head 1. This arrangement has an advantageous effect on the gas flow, the inclined inlet valve plates guiding the gases in such a way that the gas flow directs the gas into the Cylinder flows. The intake ports do not have to run steeply against the valve plate and the valves can be made shorter and therefore lighter, which has a favorable effect on the dimensions of the cylinder head or permits higher speeds.

1 and 2 also show that the valves which are at an angle to one another are controlled by two overhead camshafts, not shown.

By the same principle according to FIG. 1 and 2 also the other embodiments are formed according to Figures 3-6, wherein are omitted let channels the air valves and fuel supply ^'in the Ein¬ for ease of illustration. 3 differs from that previously described only in that an inlet channel with the associated inlet valve and the outlet channel with the valve are on one side and only one inlet channel on the opposite side, so that the one camshaft is on Intake valve and one exhaust valve and the other camshaft controls only one intake valve.

In the embodiment according to FIG. 4, there are two outlet valves to which a common outlet channel 8a is assigned. With two exhaust valves, one valve closes later than the other. If, for example, the left outlet valve 9 closes later in FIG. 1, the inlet duct 2, whose air flap (not shown in FIG. 4) opens first, also has a slightly earlier valve opening time and is located furthest away from the valve lastly closing exhaust valve 9. This allows greater valve overlap times.

The embodiment according to FIG. 5 has only one Outlet channel 8 with the outlet valve 9, but in addition to the two inlet channels 2 and 3 shown in FIG. 1, a third inlet channel 10.

In the embodiment according to FIG. 6 there is also a fourth intake duct 11 and the ducts and their associated valves are arranged somewhat closer to the cylinder head 1 and in any case in such a way that the ducts cause a vortex in their direction Generate clockwise within the cylinder, ie the channels open into the cylinder head with the inclination pointing in the same circumferential direction. The valves in the individual inlet channels and in the outlet channel are arranged in two groups such that they are at an angle and can be actuated by two overhead camshafts.

In the case of a plurality of inlet channels, these are of different sizes in terms of their clear cross-section in order to achieve different gas velocities. The inlet port, which opens first in the lower speed range, is designed for the highest gas speed. The gas velocity is slower in the inlet channels that open later, but the pressure increases. Under these conditions, the cylinder is optimally charged with increasing stroke speed and position of the piston, and the desired vortex breπsx does not come off even at maximum stroke.

In summary, the advantages of the multi-valve engine with directionally separated inlet ducts are that an uninterrupted vortex in the cylinder, a torque-favorable gas column regulation, a large valve overlap as well as relatively short valves can be realized and, as a result, an optimization of the fuel preparation due to the each inlet channel associated air injection valve and further to grό ^'possible quantities ssτ- control gas column by long UeberschneidungεZeiten and speed-dependent, further to a rapid optimum combustion by strong turbulence during the entire torque curve and higher Maximum performance with good torque characteristics through variable channel connection leads.

Claims

Patent claims

Is 1. internal combustion engine characterized by at least one valve Auslass¬ and more than one intake valve per cylinder, da¬ by that each of the intake valves (5) is assigned a separate, closable by the valve Einlasska¬ nal (2.3 _»10,11) and each inlet duct has a separately operable air flap (6) and a fuel supply (7).

2. Internal combustion engine according to claim 1, characterized ge indicates that of a plurality of separate inlet channels (2,3,10,11) at least one essentially from above and at least one further from the side and obliquely, with each additional of At the top or from the side extending inlet channel pointing in the same circumferential direction into the cylinder head (1), for the purpose of generating an uninterrupted gas vortex in the cylinder.

3. Internal combustion engine according to claim 1, wherein the exhaust valve (9) is assigned an exhaust duct (8) or two exhaust valves arranged side by side per cylinder (9) a common exhaust duct (8a), characterized in that the exhaust ducts (8, 8a) are arranged on the same side in each row of cylinders of the engine.

4. Internal combustion engine according to claim 1, characterized in that the inlet channels (2, 3, 10, 11) have a different size of the clear cross section for the purpose of generating different gas velocities.

5. Internal combustion engine according to claim 1, characterized in that at an angle to each other and by two camshafts controlled intake valves (5) and exhaust valves (9) at an angle in the cylinder head (1) arranged valve plate for the purpose of vortex-promoting gas introduction into the cylinder exhibit.

6. The method for operating the internal combustion engine according to any one of claims 1-5, characterized in that for low engine speeds at least one inlet duct is opened by means of the air flap and that for increasing engine speeds the inlet ducts are opened in a staggered manner in time by means of the respective air flap, and that the inlet channel which is furthest away from the outlet valve is opened first and that, due to different channel cross sections, inlet channels designed for gradually lower gas speeds are opened in succession.

7. The method according to claim 6, characterized in that the engine is operated with respect to the intake stroke and exhaust stroke with valve overlap times and that the first opened inlet channel has a longer valve overlap time with the last closing, most distant outlet valve than the other inlet channels Has.

8. The method according to claim 6, characterized in that the air flap and the injection in each inlet duct are regulated together in such a way that a fuel quantity dependent on the flap position is supplied.